AKT1 and neoplasm: Because NHEJ is the predominant pathway in mammals, activation of the EGFR/PI3K/Akt signaling pathway is crucial for tumor cell survival after radiation and the inhibition of Akt activity by targeting the RTK–PI3K–Akt axis suppresses faithful repair of IR-induced DNA DSBs and improves radiotherapy efficacy [203,204,205,206].